Self cleaning filter system



Nov. 29, 1960 T. R. SMITH SELF CLEANING FILTER SYSTEM 2 Sheets-Sheet 1 Filed Jan. 3, 1957 Q. Smith Wa r um, nu m MAM/f Nov. 29, `1960 T, R, sMlTH SELF CLEANING FILTER SYSTEM 2 Sheets-Sheet 2 Filed Jan. 3, 1957 a5 invern lor Q. smirk SELF CLEANING FILTER SYSTEM Thomas R. Smith, Newton, Iowa, assignor to The Maytag Company, Newton, iowa, a corporation of Delaware Filed Jan. 3, 1957, Ser. N0. 632,383

8 Claims. (Cl. 68-18) This invention relates to a self-cleaning filter system for a washing machine capable of being automatically controlled -throughout a sequential cycle of washing and uid extraction operations.

It relates specifically to that type machine in which a pump controlling the removal of fluids from the washing machine pumps in one direction during the agitation operation and then reverses its direction of rotation to pump in the opposite direction during the centrifugal extraction or drain operation. In the embodiments of my invention disclosed hereinafter the coordination of the reversal of this pump with the reversal of the drive mechanism contro-lling the washing and extraction operations is utilized to auto-V matically control the fluid flow through a self-cleaning filter during these respective operations so that a filtering of the washing fluid takes place during the agitation of the clothes within the machine while the back flushing of the self-cleaning filter is automatically accomplished during the fluid extraction or drain operation.

Briefly, my invention incorporates an imperforatetub member capable of retaining fluids during the agitation period. A drain hose is attached to this -tub and to a reversible fluid pump having its opposite side leading to an external drain. A filter is provided near the junction of the connection between this drain hose and the tub. A fluid circulation second hose provided with a check valve permitting fluid iiow in a single direction only is then attached between another portion of the tub and this opposite side of the fluid pump leading to the external drain. By coordinating the operation of the pump with that of the drive mechanism controlling the machine, t it is possible during the agitation period to circulate fluids from the tub down through the circulation hose and its check valve, through the pump and then up the drain hose an and through the filter before the fluid is returned to the tub during the agitation of the clothes in this fluid.

When the tub is drained during the extraction period, the pump is reversed with a reversal of the drive mechanism controlling the machine allowing the lluid in the tube to be pumped from the tub through the lter in a reverse direction to back flush that iilter as` the lluid is pumped to the external drain.

` In the accompanying drawings:

Figure 1 is a side elevation, partially bro-ken away, showing a washing machine incorporating my invention; l Figure 2 is a sectional view taken on line 2--2 of Figure 1 showing the positioning of the self-cleaning filter at the lower portion of the outer tub;

Figure 3 is a fragmentary sectional view taken on line 3-3 of Figure 2;

Figure 4 is a perspective view of the'self-cleaning iilter shown in Figure 1;

`Figure 5 is a fragmentary view similar to that of Figure 2showing a second embodiment of my invention; lv'Figure 6 is a fragmentary sectional view taken on line o'fFigure 5;A 'y

n 2,961,862 Patented Nov. l29, 1960 ice' Figure 7 is a fragmentary sectional view taken oriI line 7 7 of Figure 5;

Figure 8 is a sectional view of a modified valve cori-` struction for my iiuid circulation system; and,

Figure 9 is a view similar to Figure 8 showing a sec-` ond position of the diverter valve shown in Figure 8.

In the accompanying drawings, there is shown a base frame 10 mounted on adjustable feet 11 and provided with a supporting dome 12 rising out of a centrally lo-y cated depression 13 in base frame 10. Dome 12 serves; as a mounting for a drive assembly 1'4 such as that dis-1 closed in the John D. Goodlaxson application, Serial' No. 505,231, filed May 2, 1955, and assigned to thel same assignee as that of the instant application.

Base frame member 10 also supports the up-ended reversible motor 15 and the water pump 16 which, like a. drive assembly 14, is driven by motor 15 through belt; 17 on the under side of the base frame 10. Numerally 19 designates the groove of pulley 18 which serves as ther input member for the drive assembly 14.

Cabinet 21, attached to and enclosing base frame 10' together with the drive and tub assemblies suppoitedl thereby, is provided at its upper end with a dependingl annular flange 22 defining an access opening into the washing machine apparatus which is normally covered by access door 24.

In Figure 1, it can be seen that dome 12 in base frame 1t) is provided with friction pads 26 at its periphery adjacent the opening 27 -formed by the uppermost portion of the truncated dome 12. An umbrella-like support memberV 28 rests on these friction pads 26 and is provided with three equally spaced ears 29 for three centering springs 31 which are fastened to brackets 32 on base frame 10. This arrangement centers support member 2S on dome 12 and restrains it from rotation relative to base Iframe 10.

Threaded into the umbrella support member 28 is a member 34 of substantially frusto-conical configuration which serves as a housing for drive assembly 14 of the previously identified Goodlaxson application, Serial No. 505,231. Housing member 34 cooperates with umbrella support member 28 by gripping the outer race of a thrust bearing 35 which is provided with a tapered inner race. Mating with and seated in this tapered inner race of bearing 35 is the spin tube or shaft 37 which journals a power shaft 38 also extending into the drive assembly 14; With this construction all weight placed on the spin tube 37, housing 34 and on umbrella member 28 may be used to an advantage to provide ample frictional forces between umbrella member 28 and the friction pads 26 for damping nutational movements of the shafts 37 and 38 relative to dome 12 while permitting rotational movement of spin tube 37 in thrust bearing 35.

While the details of the Goodlaxson assembly forming the basis of the previously identified application Serial No. 505,231 are not essential to the construction of the instant invention, its operation can be briefly explained for environmental purposes. Upon energization of motor 15 in a direction to rotate pulley 18 in a counterclockwise direction as viewed from the bottom of Figure 1, power shaft 38 is rotated in this same direction While spin shaft 37 is held against rotation by appropriate braking mechanism within housing 34. Upon reversal of motor 15, spin shaft 37 is released for rotation to allow shafts 37 and 38 to be spun in unison in a clockwise direction.

The direction of rotation of motor 15 is dependent I upon the programmed sequence determined and controlled rotated as determined by the direction of rotation imparted to pulley 18 while permitting their nutation about a vertical axis at all times. In the washing machine illustrated in the accompanying drawings, shafts 37 and 38 nut-ate on a point determined by the intersection of the vertical axis of rotation with a horizontal plane bisecting groove 19 of pulley 18.

Now with reference to the tub assembly, it will be noted that umbrella support member 28 is provided with three recessed upstanding lugs 41 spaced equally from each other and alternately around member 28 with respect to the three ears 29. While not entirely obvious from Figure 1, it will be apparent from this description that there are three lugs 41 spaced 120 from each other, each of which is 60 removed from an adjacent ear 29.

Fastened within the recessed lugs 41 by connectors 42 are the three tub brace members 43 which are, in this embodiment, of channel-like cross section. Brace members 43 extend outwardly and upwardly from the umbrella support member 2.8 to join the nonrotatable impcrforate outer tub 44 through tub connectors 45 to form an inverted tripod support for tub 44. The tub 44 is provided with a bottom wall 47 in which is formed a C-shaped gutter 48 having its lowest portion converging Iinto the drain outlet 49 which in turn communicates with the water pump 116 through the flexible hose 51.

The nonrotatable outer tub 44 is provided with a removable crown 52 which permits removal of the rotatable inner clothes receptacle or basket 53 nested within tub 44. The clothes receptacle 53 has a perforate bottom wall 54 and a perforate cylindrical side wall 55 which carries a concrete inertia ring 56 at its uppermost end. A conventional oscillating type agitator 57 is mounted within the inner tub or basket 53 to provide the properl agitation of fabrics placed within the tub assembly thus formed.

In order to drive agitator S7 during the agitation period and rotate receptacle 53 during the tiuid extraction cycle, the following connections to the drive assembly 14 are provided. Spin tube 37, extending into drive assembly 14, carries at its upper end the lowest gear case cover 58 which in turn is bolted to the upper gear case cover 59 carrying counterweight 61 which balances the conventional motion unit housed by covers 58 and 59 and driven by power shaft 38. While not shown in the accompanying figures in detail, upper gear case cover 59 extends upwardly through a iiuid tight bearing formed in the tub bottom wall 47 and is rigidly attached to the basket' bottom wall 54 by appropriate connections the detail of which is not necessary for the understanding of the instant invention.

From an inspection of the accompanying drawings it can be seen that tub 44 is connected to a second hose member 63. This hose 63 serves as a fluid circulation hose and is, in this modification, attached to the circulation outlet 62 provided in bottom wall 47 and located diametrically opposite drain outlet 49. Circulation hose 63 is provided with a check valve 64 which opens easily under fluid pressure from above to permit unidirectional uid flow in a downward direction through hose 63 but which closes once pressure is applied from the lower side of that check valve.

Circulation hose 63 forms a T-connection with the drain hose 66 which is connected between pump 16 and an elevated drain 67 provided by an adjacent reservoir 68. While the reservoir 68 is desirable for suds saving purposes, it serves only as an elevated drain in this illustrative embodiment and would not be necessary if an additional valve were used in the drain hose 66 at a point beyond the T intersection formed with the circulation hose 63 in order to control the drainage of fluids from tub 44. In order to clarify the hose connection details for this illustrative machine, hose 66 has been shown as projecting through the front panel rather than through the back panel of the machine as is done in lactual practice.

To filter fluids circulated through the illustrative machine, a self-cleaning filter plate 70 is provided in tub y44 near the junction of drain hose 51 with the tub bottom wall 47. Filter member 70 is rigidly attached to tub 44 in a spaced relationship to basket 53 and the tub bottom wall 47 in order to allow relative rotation to take place between basket 53 and tub 44. Filter 70, in the embodiment shown in Figures 1 to 4, is sector shaped and is provided with down-turned sides 71 and a yslightly downturned throat portion 72 to aid in the retention of lint and thread particles filtered from the fiuids pumped through filter 70.

Filter 70, as shown in Figure 2, is perforate and is positioned above the drain outlet 49 to assure that all liquids passing through hose 51 will flow through or around filter 70. It is preferable in the construction of this filter arrangement that a portion of the liuid be bypassed around filter member 70 so that it will not be possible to prevent water from passing through hose 51 due to a clogged filter caused by improper loading or operation of this machine. In the embodiment of Figures l to 4, space is therefore provided between gutter l48 and down-turned edges 71 as well as between bottom wall 47 and the depending edge 72 to allow some fluid to bypass filter 70.

In operation during the agitation period, rotation of drive assembly pulley 18 by motor 15 in a counterclockwise direction as viewed from the bottom of Figure l causes spin shaft 37 to be braked by mechanism within assembly 14 while power shaft 38 causes agitator 57 to oscillate within tub S3 in a conventional manner to cleanse the clothes. During this agitation period, the rotation of pump 16 is such that it tends to pump fiuid upwardly through drain hose 51 into tub 44 as the washing fluid passes downwardly through check valve 64 and fills the horizontal portion of drain hose 66 between pump 16 and check valve 64 in the direction of the dotted arrows of Figure l. This fluid is pumped upwardly through drain hose 51 by pump 16 and passes through and around filter member 70 which filters from the washing fluid a portion of the Lint, ravelings or thread particles separated from the clothing during the agitation process. The filtered water leaving filter 70 passes through and around basket 53 and mixes with the washing `fluid within tub 44 before passing again into the circulation hose 63 to repeat `its circulatory path through filter 70.

Upon reversal of motor 15 during the centrifugal extraction periods, the spin tube 37 is released from its braked position and is rotated in unison with shaft 38 by pulley 1S to rotate basket 53 and effect an extraction of fluids from the wet fabrics retained within that revoluble clothes receptacle. During this spin period, the rotation of pump 16 is also reversed with the result that water flow through that pump reverses causing `fluids to be pumped from tub 44 through hoses 51 and 66 to drain 67 by way of reservoir 68 as shown by the solid arrows in those hoses in Figure 1.

In this drainage process washing fluids passing from tub 44 reverse their fiow through filter 70 and ush that filter free of collected lint and thread particles placing it in a cleansed condition preparatory to the next agitation cycle. It will be noted that as the washing fluids pass from pump 16 and into drain hose 66 no fluid will be returned to tub 44 through circulation hose 63 by reason of that hose being closed by check valve 64.

By shaping the filter plate 70 in the manner shown in Figure 2, the fluid pumped from tub 44 during the centrifuging operation not only flushes that filter free of lint but also scours the bottom of the tub area free of accumulated sand and dirt deposits as described and claimed in my co-pending application, Serial No. 587,718, filed May 28, 1956, now Patent No. 2,900,812, of August 25, 1959, and assigned to the assignee of the. instant invention.

. Figures 5, 6 and 7 illustrate a second embodiment of my invention which differs from the first described embodiment primarily by the degree of its radial projection toward the center of tub 44. Figure 5 shows the modified filter 80 as being fastened to tub 44 in a manner similar to the connection of filter 70 to that tub in Figure 2. Filter 80 extends across drain opening 49 and bridges the gutter 48 before terminating in a depending flange 81 which projects practically to tub bottom wall 47. Filter 80 is also provided with end flanges 82 which approach bottom Ywall 47 but do not completely close gutter 48. This provides a filter for fluid passing into tub through hose 51 without unduly impeding fluid flow from the tub during the drainage process. While the fluid patterns produced by fluid flow through filter 80 of this embodiment differ from those of filter 7 0 of the first embodiment, the basic function and operation of filtering particles of lint and thread particles from fluid circulated by pump 16 through the respective outlets 62 and 49 remains the same in both embodiments.

i While both filters 70 and 80 have been shown to permit some fluid to bypass each of these filters, it is also within the spirit of this invention to filter all fluids passing through hose 51 either by placing a filter completely over drain outlet 49 or within the hose portions through which water is both circulated and back flushed by the drainage process.

A In addition, while both illustrative embodiments of my invention have shown a stationary fluid pump capable of pumping in one direction during the agitation period and in an opposite direction during the centrifugal extraction period by controlling the direction of rotation of the main driving motor, it is also considered to be within the scope of this invention to use a unidirectional drive motor in conjunction with a pump capable of being shifted between .two oppositely driven sheaves or belt surfaces to accomplish this same desired reversal of fluid flow during the agitation and drain periods.

It is also considered to be within the scope of this invention to utilize two oppositely driven pumps in conjunction with a diverter valve controlling fluid flow into these pumps to control reversal of fluid flow through the filter System in a similar manner.

Figures 8 and 9 illustrate a positive diverter valve assembly which may be substituted for the check valve construction shown in Figure l. The diagrammatic Figures 8 and 9 show a valve body 84 as being inserted in between the two-piece hose having one portion leading to pump 16 land designated by reference character 66 and a second portion leading to an external drain and designated by the reference character 66h. Circulation hose 63 connects to valve body 84 in a T connection similar to its connection to hose 66 in Figure 1.

Mounted Within valve body 84 and movable between the positions shown in Figures 8 and 9 is the valve element 85 which may be controlled by `a crank-link-solenoid construction, etc. (not shown). With this actuator system valve element 85 may be moved into either of its positions whenever fluid flow through pump 16 is reversed.

For example, during the agitation period when fluid is flowing in the direction of the dotted arrows of Figure 1, Valve element 85 will be positioned as shown in Figure 8 toprovide that desired flow path. In that position communication is established between circulation hose 63 and hose portion 66 while all fluid flow through hose portions 66b is terminated. During the centrifugal extraction period or drain operations when fluid flow follows the pattern of the solid arrows in Figure l, valve element 85 is moved into the posi- Ytion shown in Figure 9 to prevent fluid flow into hose 63 While allowing hose portion 66a to communicate directly with hose portion 66h.

This modification, which may kbe duplicated by other diverter valve constructions, positively prevents air from entering hose portion 66L from hose portion 661, during the agitation period while positively preventing fluid flow into hose 63 during the drain operations. In addition, this construction eliminates the necessity for the high drain through reservoir 68 as shown in Figure 1 since Iall fluid flow through hose portion 66 is terminated during the agitation period with valve element positioned as shown in Figure 8.

This modification, like that of Figure l, permits the filter for filtering lint and foreign particles from the washing fluid to be placed either in tub 44 as shown in Figure 1 or in either of hoses 51 or 66 which provide the two-way flow necessary for back flushing the filter.

I claim:

1. A self-cleaning filtering system for a Iwashing machine operable through an agitation period and a drain period for cleansing fabrics comprising, la tub adapted t0 contain fluid during said agitation period, a fluid conduit connected to and communicating with said tub, a reversible fluid pump having one side connected to and communicating with said fluid conduit, a drain hose, said pump having lan opposite side connected to said drain hose, a circulation conduit connected to and communicating With said tub at a point diametrically opposite the point of connection between said tub and said fluid conduit, said circulation conduit being further connected to and communicating with said drain hose, a check valve in said circulation conduit providing unidirectional fluid flow therethrough, a filter located within said tub and positioned over the point of connection between said fluid conduit and said tub to filter fluid passing through said fluid conduit, means for rotating said pump in a first direction during said agitation period to circulate fluid through said circulation conduit and said check valve and said filter to filter said fluid of lint and thread particles separated from said fabrics during said agitation period, said means reversing the direction of rotation of said pump during drain period to discharge fluid from said tub through said filter in a reverse direction to back flush said lter.

2. A self-cleaning filtering system for a Washing machine operable through-an agitation period and a centrifugal extraction period for cleansing fabrics comprising, a tub adapted to contain fluid during said agitation period, a revoluble clothes basket within said tub, a fluid conduit connected to and communicating with said tub, a reversible fluid pump having one side connected to and communicating with said fluid conduit, a drain conduit, said fluid pump having an opposite side connected to and communicating with said drain conduit, a circulation conduit connected to and communicating with both said tub and said opposite side of said pump, a filter located within said tub and positioned between said tub and said basket over the point of connection between said fluid conduit and said tub to filter fluid passing through said fluid conduit, means for rotating said pump in a rst direction during said agitation period to circulate the fluid from said tub through said circulation conduit and said fluid conduit and back into said tub through said filter to filter said fluid of lint and thread particles separated from said fabrics during said agitation period, said means reversing the direction of rotation of said pump during said centrifugal extraction period to discharge fluid from said tub through said filter in a reverse direction to back flush said filter.

.3. A self-cleaning filtering system for a washing machine operable through an agitation period and a centrfugal extraction period for cleansing fabrics comprising7 a tub adapted to contain fluid during said agitation period a revoluble clothes basket nested within said tub and having a bottom wall spaced from said tub, a fluid conduit connected to and communicating with said tub, a reversible fluid pump having one side connected to and communicating with said fluid conduit, means dening an elevated drain elevated above said fluid, a

drain hose communicating with said elevated drain, said fluid pump having an opposite side connected to and communicating with said drain hose, a circulation conduitl connected to and communicating with both said tub and said drain hose, a valve within said circulation conduit controlling fluid flow therethrough, a filter mounted within said tub over the point of connection between said fluid conduit and said tub and projecting from the periphery of said tub into the space between said tub and said basket bottom wall to filter fluid passing through said fluid conduit, means for rotating said pump in a first direction during said agitation period to circulate fluid through said circulation conduit and said fluid conduit to filter said fluid of lint and thread particles separated from said fabrics during said agitation period, said means reversing the direction of rotation of said pump during said centrifugal extraction period to discharge fluid from said tub through said filter in a reverse direction to back flush said filter during said centrifugal extraction period.

4. A self-cleaning' filtering system for a washing machine for receiving fabrics to be washed and operable through an agitation period and a drain period comprising, a tub adapted to contain fluid during said agitation period, a clothes basket within said tub, first and second fluid outlets in said tub, conduit means interconnecting said outlets, a valve in said conduit means, a drain hose communicating with said conduit means, a fluid filter positioned within said tub between said tub and said basket to filter fluid passing from said conduit means into said tub through said first outlet, pump means in said conduit means for pumping fluid from said tub through said second outlet and into said tub through said first outlet and said filter during said agitation period to filter from said fluid those lint and thread particles separated from said fabrics and suspended in said fluid, and control means controlling said pump means for reversing fluid flow through said filter and said first outlet to back flush said filter through said drain hose during said drain period.

5. A self-cleaning filter system for a washing machine for receiving fabrics to be washed and operable through an agitation period and a centrifugal extraction period comprising, a tub adapted to contain fluid during said agitation period, a clothes basket revolubly mounted within said tub, first and second fluid outlets in said tub, conduit means interconnecting said outlets, a valve in said conduit means, a drain hose communicating with said conduit means, a fluid filter covering said first outlet and positioned within said tub in spaced relationship to said tub and to said basket to filter fluid passing into said tub through said first outlet, pump means in said conduit means for pumping fluid from said tub through said second outlet and into said tub through said first outlet and said filter during said agitation period to filter from said fluid those lint and thread particles separated from said fabrics and suspended in said fluid, and control means controlling the rotation of said basket and operation of said pump means for rotating said basket and reversing fluid flow through said filter and said first outlet to back flush said filter through said drain hose during said centrifugal extraction period.

6. A self-cleaning filter system for a washing machine for receiving fabrics to be washed and operable through an agitation period and a centrifugal extraction period comprising a tub adapted to contain fluid during said agitation period, a clothes basket revolubly mounted within said tub, first and second fluid outlets in said tub, conduit means interconnecting said outlets, a valve in said conduit means, adrain hose communicating with said conduit means, a fluid filter covering said first outlet and positioned within said tub between said tub and said basket to filter fluid passing into said tub through said first outlet, said filter having at least a portion of its periphery flanged toward said tub to retain lint and thread particles within said filter, pump means in said conduit means for pumping fluid from said tub through said second outlet and into said tub through said first outlet and said filter during said agitation period to fil-ter from said fluid those lint and thread particles separated from said fabrics and suspended in said fluid, and control means controlling the rotation of said basket and the operation of said pump means for rotating said basket and reversing the fluid flow through said filter and said first outlet to back flush said lter through said drain hose during said centrifugal extraction period.

7. A self-cleaning filter system for a washing machine for receiving fabrics to be washed and operable through an agitation period and a centrifugal extraction period comprising, a tub adapted to contain fluid during said agitation period, a clothes basket revolubly mounted within said tub, first and second fluid outlets in said tub, conduit means interconnecting said outlets, a diverter valve in said conduit means having a drain port therein and regulating communication between said rst and second outlets and between said first outlet and said drain port, filter means positioned adjacent said first outlet and between said tub and said basket for filtering foreign particles from fluid passing through said conduit means, pump means in said conduit means for pumping fluid from said second outlet through said first outlet and said filter means during said agitation period to filter foreign particles from said fluid, and control means controlling the rotation of said basket and operation of said pump means for rotating said basket and reversing fluid flow through said filter means and'said first outlet to back flush said filter means through said drain port during said centrifugal extraction period.

8. A washing machine operable through an agitation period and a centrifugal extraction and drain period for cleansing fabrics comprising, a tub adapted to contain fluid during said agitation period, a revoluble clothes basket with-in said tub, an agitation member within said basket, first and second fluid outlets in said tub, conduit means interconnecting said first and second outlets, a drain conduit connected to said conduit means, filter means for filtering said fluid passing through said conduit means, pump means in said conduit means for circulating said fluid from said second outlet through said filter means and to said tub during said agitation period to filter from said fluid the lint and thread particles separated from said fabrics and suspended in said fluid, drive means to drive said agitation member during said agitation period and said revoluble clothes basket in said centrifugal extraction period, and control means for reversing fluid flow through said filter means and said first outlet to back flush said filter means during said drain'period.

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